Massive ice near Eureka (NU) (M. Paquette)

Ice can be quite abundant in permafrost, but its origin, whether it has been buried or has formed in-situ, is sometimes hard to tell. This picture shows massive ice underlying a thick marine deposit (mostly clay). It was taken in late July in 2013, near the Eureka airport in Nunavut in an active retrogressive thaw slump, a landform created by ice-rich permafrost degradation. The two dark lines crossing the ice mass is reminiscent of structures that can be seen in glaciers, and indicate a possible buried origin for this ice. Analysis of the cryostratigraphy, of the geochemistry and of the crystallography of the ice can help tell the difference. An example of this type of work can be found in this article and in this presentation by lab member Stéphanie Coulombe.